Graphene oxide nanofiltration membrane for efficient dye separation by β-FeOOH intercalation and dopamine surface modification

Abstract

Graphene oxide (GO) membranes have been extensively studied for the separation and purification of dye wastewater. Improving the stability, permeability and self-cleaning ability of these materials is urgently needed for the purification of complex dye wastewater. In this study, we developed a simple and effective method to insert ternary β-iron hydroxide (β-FeOOH) between GO nanosheets and modify the membrane surface with dopamine hydrochloride (PDA) to solve this problem. The pure water flux of the composite membrane was 9 times higher than that of the pure GO membrane (92.82 L m−2h−1), and the rejection of dye molecules larger than 400 Da was consistently greater than 99 %. The PDA/GO-β-FeOOH2 composite membrane was operated for 50 h (with xenon lamp irradiation to clean the membrane surface) with a flux of 34.98 L m−2h−1 and a rejection rate consistently higher than 98.5 %.